- Grade 2 or greater severity clinical safety lab values (according to the toxicity table, Section 11.1.1.2) that do not return to Grade 1 or less prior to the second vaccination. If the clinical safety lab values return to Grade 1 or less, vaccination should be rescheduled within the acceptable window for the second vaccination - see Section 10.3.3. Subjects who experienced a Grade 3 or above clinical safety laboratory adverse event since receipt of Dose 1 should be excluded from receipt of second vaccination. Subjects who had a Grade 3 or above clinical safety laboratory adverse event prior to first vaccination will be evaluated by the site principal investigator and DMID Medical Monitor to determine receipt of second vaccination.